Solar Neutrinos: Global Analysis with Day and Night Spectra from SNO

We perform global analysis of the solar neutrino data including the day and night spectra of events at SNO. In the context of two active neutrino mixing, the best fit of the data is provided by the LMA MSW solution with ∆m2 = 6.15 ·10−5 eV2, tan2 θ = 0.41, fB = 1.05, where fB is the boron neutrino flux in units of the corresponding flux in the Standard Solar Model (SSM). At 3σ level we find the following upper bounds: tan2 θ < 0.84 and ∆m2 < 3.6 · 10−4 eV2. From 1σ-interval we expect the day-night asymmetries of the charged current and electron scattering events to be: A DN = 3.9 +3.6 −2.9% and A ES DN = 2.1 +2.1 −1.4%. The only other solution which appears at 3σ-level is the VAC solution with ∆m2 = 4.5 · 10−10 eV2, tan2 θ = 2.1 and fB = 0.75. The best fit point in the LOW region, with ∆m2 = 0.93 · 10−7 eV2 and tan2 θ = 0.64, is accepted at 99.95% (3.5σ) C.L. . The least χ2 point from the SMA solution region, with ∆m2 = 4.6·10−6 eV2 and tan2 θ = 5·10−4, could be accepted at 5.5σ-level only. In the three neutrino context the influence of θ13 is studied. We find that with increase of θ13 the LMA best fit point shifts to larger ∆m 2, mixing angle is practically unchanged, and the quality of the fit becomes worse. The fits of LOW and SMA slightly improve. Predictions for KamLAND experiment (total rates, spectrum distortion) have been calculated. Pacs numbers: 14.60.Lm 14.60.Pq 95.85.Ry 26.65.+t